This invention relates to an electronic apparatus provided with a cooling device for circulating a cooling medium, such as water.
In one example of a conventional electronic apparatus, as disclosed in JP-A-6-266474, a printed circuit board, having a heat-generating element mounted thereon, is contained in a housing forming a shell of the electronic apparatus, and a display unit housing, having a display panel, such as a liquid-crystal panel, is pivotally mounted on this housing. A heat-receiving jacket is mounted on the heat-generating element in this electronic apparatus, and a cooling medium (such as water), that is sealed in this heat-receiving jacket, absorbs the heat generated by the heat-generating element is fed to a heat-dissipating pipe that is mounted on an inner surface of the display unit housing by a pump (liquid-moving device). The heat-receiving jacket, the heat-dissipating pipe and the pump are connected to one another by flexible tubes to jointly form a so-called water cooling-type cooling device.
JP-A-7-142886 discloses an example in which the housing of the water-cooled electronic apparatus, as disclosed in JP-A-6-266474, is made of metal.
In the above examples, the heat generated in the heat-generating element is transferred to the heat-receiving jacket, and the liquid, which absorbs and stores this heat, is moved from the heat-receiving jacket to the heat-dissipating pipe by the liquid-moving device, so that the heat is transferred from the heat-dissipating pipe to the housing and is radiated to the ambient atmosphere.
In large-size computers, semiconductor devices are cooled by a cooling medium, such as water, as is well known in the art.
In the above-described art techniques, the heat generated in the semiconductor device is merely transferred to the display side by a cooling device of the water cooling-type. Namely, according to research by the inventors of the present invention, the above-described techniques do not take into consideration the possibility of forming the cooling medium-circulating pump so as to produce a thin design. In other words, a pump for circulating water is merely provided, and the cooling medium liquid is circulated at a typical liquid-moving rate and operating pressure, which are larger than required, thereby effecting excessive cooling. Therefore, the pump is large in size, and so it has been difficult with such an approach to form a portable electronic apparatus having a thin design.
It is therefore an object of this invention to provide an electronic apparatus in which the size and operating condition of a liquid-moving device are optimized by determining those liquid circulating conditions which are necessary and sufficient for an increased amount of heat occurring in a heat-generating element, as a result of an improved processing performance of the electronic apparatus, thereby providing an electronic apparatus that is suited for a compact and thin design.
According to a first aspect of the present invention, there is provided an electronic apparatus that has a first housing having a semi-conductor device mounted therein; a second housing having a display device disposed therein, which second housing is pivotally supported on the first housing; a heat-receiving member held in thermal contact with the semi-conductor device; a heat-dissipating member held in thermal contact with an inner surface of the second housing; liquid-moving means located in the first housing so as to move a liquid medium between the heat-dissipating member and the heat-receiving member; and a tube interconnecting the heat-receiving member, the heat-dissipating member and the liquid-moving means, the liquid-moving means being made to have a thickness smaller than the thickness of the first housing.
According to a second aspect of the present invention, there is provided an electronic apparatus that has a first housing having a semi-conductor device mounted therein; a second housing having a display device disposed therein, which second housing is pivotally supported on the first housing; a heat-receiving member held in thermal contact with the semi-conductor device; a heat-dissipating member held in thermal contact with an inner surface of the second housing; liquid-moving means located in the first housing so as to move a liquid medium between the heat-dissipating member and the heat-receiving member; and a tube interconnecting the heat-receiving member, the heat-dissipating member and the liquid-moving means, the second housing being made to have a surface temperature, as a value of temperature rise, that is maintained at not more than 25xc2x0 C. above the ambient temperature.
According to a third aspect of the present invention, there is provided an electronic apparatus that has a first housing, having a semi-conductor device mounted therein; a second housing having a display device disposed therein, which second housing is pivotally supported on the first housing; a heat-receiving member held in thermal contact with the semi-conductor device; a heat-dissipating member held in thermal contact with an inner surface of the second housing; and a tube connected to liquid-moving means for moving a liquid medium between the heat-dissipating member and the heat-receiving member, the liquid-moving means being operated to provide a liquid-circulating rate not less than 120 xcexcL/SEC.
The liquid-circulating flow rate brought about by the liquid-moving means is preferably not more than 1200 xcexcL/SEC.
The cooling medium liquid may be circulated at a flow rate not less than a value Q defined by the following formula, in order to cool the heat-receiving member down to a temperature TWJ:
Q=6xc2x7Axc2x7QC/(12xc2x7Axc2x7(TWJxe2x88x92TA)xe2x88x92QC)/(xcfx81xc2x7CP)
wherexcfx81 and CP represent the density and specific heat of the cooling medium liquid, respectively, QC represents the amount of heat occurring in a CPU (semi-conductor device), TA represents the ambient temperature, and A represents the area of a heat-dissipating metal sheet.
The height of the liquid-moving means may be not more than 30 MM.
The liquid-moving means may have a flattened shape, and may be arranged to be flat in the direction of the thickness of the first housing.
The inner diameter of the tube, which interconnects the heat-receiving member, the heat-dissipating member and the liquid-moving means, may be larger than the inner diameter of the heat-dissipating member.
The liquid discharge pressure of the liquid-moving means may be not less than about 1.7xc3x97104 Pa.